# 求解1-10的和
# result = 0
# i=1
# while i <11:
#     result = result + i
#     i+=1
# print (result)

# 求解1到100奇数的和
result = 0
i = 1
while i < 101:
    if i%2 ==1:
        result += i
    i += 1
print(result)


